Refrigeration system



June 27, 1939. H, w NEV|N 2,163,799

EFRIGERATION SYSTEM Filed Sept. 8. 19256 2 Sheets-Sheet l INVENTOR 4 r r f s r am BW Z ATTORNEY June 27, 1939. H, w NEWN 2,163,799

REFRIGERATION SYSTEM Filed Sept. 8, 1936 2 Sheets-Sheet 2 :Suventor 3km# @Mxaw l :in close the liquid stop valve.

Patented June 27, 1939 UNITED vSTATES REFRIGERATION SYSTEM Harry W. Nevin, Chicago, Ill., assignor to Industrial Patents Corporation, Chicago, Ill., a corporation ofv Delaware Application September 8, 1936, Serial No. 99,775

1ov claims.

This invention relates to means for automatically opening and closing the low pressure or p suction line of a refrigeration system by emi ploying the differential in pressure between the 5 high pressure or liquid line of the system and the low pressure line.

This application is a continuation in part of my application entitled Refrigeration system, Serial No. 743,848, led September 13, 1934, which l application was abandoned in favor of this application September 16, 1936.

One of the objects of the invention is to provide a refrigeration system in which the temperature of a refrigerated space may be accuratel ly controlled by automatically opening and closing the suction line from the evaporator in a promptv and positive manner. Another object of the present invention is to provide for refrigeration systems a simple, prac- 20. tical and efficient automatically operating pressure actuated suction stop valve of strong, dur'able and comparatively inexpensive construction designed to be connected inthe suction line and the liquid line of a"refrigeration system between 33 the float Valve of the cooling coil and the liquid stop valve of the refrigeration system and adapted lto prevent further refrigerative eiect at a predetermined time as for instance when a thermostat in the refrigeration chamber operates to A further object of the invention is tov provide a pressure actuated suction stop valve of this character adapted to prevent the flow of gas through the suction line to the condenser or :i5 compressor when the now of liquid through the liquid line is shut oi and permit a free flow f. liquid through the liquid line and a free flow of gas through the suction line when the liquid 'stop valve is open and capable also of effectively .1o preventing counterflow of gas through it whenthe liquid ow is cut oil?.v4 v

A further object of the invention,- is to provide a pressure actuated suction stop valve adapted to allow considerable liquid pressure to be applied to it whereby a positive opening of the suction line is effected when the liquid stop valve is opened. to permit ow` of the liquid to the cooling or expansion coil.

A further object of the invention is tov provide means for controlling the speed of operation of the suction stop valve so that the opening of the same may be retarded to the desired extent and a full opening of the suction stop valve assured at the desired time with relation tothe 55 flow of the liquid to the cooling coil.

Another object of the invention is to provide a pressure actuated suction stop valve which will be characterized by an exceedingly low cost of operation and maintenance compared with the means heretofore employed for controlling the 5 now through the suction and liquid lines of a refrigeration system. i

As will be apparent from the description which follows, the present invention involves the introduction of a stop valve interposed athwart` l0 the high pressure section and the low pressure section of a' fluid line having relatively high pressure and low pressure sections.

It is well known of course, that refrigeration systems employ a iiuid line having relatively high `15 pressure and low pressure sectior The ammonia comes from the compressor under relatively high pressure and proceeds through the high pressure section of the line to the evaporator, existing in this section of the line as a liquid. In the evaporator, the ammonia passes to the gaseous phase and returns to the compressor under relatively lower pressure to be compressed and recirculated.

It is, of course, common to provide thermostatic means for stopping the ow of liquid from the compressor, this normally being effected by the use of a thermostat which operates to stop the operation 'of the compressor at a predetermined temperature of the refrigerated space.

Refrigeration plants may be considered for present purposes as being of two types, namely, single chamber installations and multiple chamber installations.' In single chamber installations, it is sufiicient to provide means for stopping the compressor when the temperature is at the desired point and to start the compressor when the temperature has risen above a selected point.

In multiple chamber installations, two or more 40 spaces such as rooms or brine tanks are refrigerated from a single compressor and condenser.

In such installations, a separate thermostat in each chamber operates to perform two functions.

.The first is to Iclose and break an electrical circuit leading to that chamber from a magnetic starting switch on the compressor. The second function is necessitated by the fact that although the circuit may be broken by the thermostat in one chamber, it may be kept closed by 50 the thermostat in another chamber so that the compressor continues to operate. This second function is to operate 'a magnetic liquid stop valve in the liquid line leading to the chamber in question. After the ow of liquid to the 55 evaporator has been cut oi by the magnetic liquid stop valve, it is necessary to economical controlled operation to close the suction line from the evaporator to preventI further evaporaof a valve solely by the employment of a solenoid of any practicable dimensions. 'Ihe usual solenoid employed has a total lifting power of but three to five pounds and must operate against a pressure differential of about thirty pounds per square inch, or a total pressure of about ninetyfour pounds in a two inch line.' An unloader employs the pressure of the line to unseat the valve when the solenoid opens a needle valve to reduce the pressure within the unloader piston.

The necessity of closely tting the piston in the valve cylinder to prevent excessive gas leakage often results in the piston sticking and the` coil burning out. Since there can be no refrigeration on the refrigerated space unless the suction line is opened, it is obvious that the failure of the valve is tantamount to a failure of the system. It is immaterial whether the failure of the valve is due to stickingor the burning out of the coil.

The present invention affords positive control of thev suction line valve without the employment of electro-magnets or pilot valves. In the 4 case of magnetic valves, the object is to overcome the suction line pressure by means of magnetic power and unloaders. In the present invention, the high pressure of the liquid line is utilized to readily overcome the lesser pressure of the suction line.

i In an ordinary installation employing a two inch suction line, assuming a pressure of one hundred fifty pounds on the liquid line, the total differential in pressure available to actuate the suction line valve is approximately fourhundred pounds.

It will be understood that the present invention is not limited to any particular valve or mechanical structure but is directed broadly to the employement of liquid line pressures to operate suction line valves in refrigerationsy'stems.

In the drawings, similar reference characters in the several gures indicate similar elements.

Figure` 1 is a diagrammatic view of a refrigeration system employing the present invention.

Figure 2 is a central vertical sectional view of 'a pressure actuated suction stop valve constructed in accordance with this invention.

Figure 3 is a horizontal sectional View taken substantially onthe line 2 2 of Figure 2.

Figure 4 is a similar View on the line 3 3 of Figure 2. 'Ihe operation of the present invention may be readily understood by reference to Figure 1 in which compressor lill, driven by motor 902, forces compressed gas through pipe 93 to condenser id. The liquid from condenser ld passes into receiver m5, thence through pipe lut to pipes it? and il. Pipe im leads to evaporators not shown. Magnetic liquid stop valve Nid isil. Pipe H3 leads to the compressor from other evaporators not shown. Motor H02 is started by magnetic switch il@ controlled by thermostat m9.

Valve il@ is shown in detail in Figures 2, 3, and and comprises in its construction a tubular main valvev body i constituting the' upper portion of the body, or casing of the device and forming a longitudinal passage having upper and lower cylindrical chambers 2 and 3 and provided With a gas inlet i and a gas outlet 5 communieating with `the gas inlet by passages 6 and 'l extending inwardly from the gas inlet andthe gas outlet and communicating with the upper cylindrical chamber 2. The gas inlet 4 is located at a higher elevation than the gas outlet 5 and the upper cylindrical chamber 2 of the t main valve body i is provided with a valve seat 8 located between the gas inlet d and the gas outlet 5 and adapted vto receive an upper valve disk 9 for closing communication between the gas inlet l and the gas outlet 5 for shutting off the flow of the gas through the suction line from the cooling or expansion coil of a refrigeration system to the compressor or condenser thereof.

The pressure actuated suction stop valve is applicable to refrigerating systems having a point of controlled varying pressures, the twok pressures being the evaporator and the condenser pressures. The passage 6 extends directly from the gas inlet d to the upper cylindrical chamber 2 and the passage i which extends inwardly from the gas outlet extends across the main valve' reduced porseat. Grooves i3 in the walls of upper valve disk S serve to permit gas passage between chamber.

2 and passage 6 to equalize the pressure. The passage 6 is enlarged as illustrated at i4, thus permitting pressure equalization on all sides.

The upper valve disk `9 is urged downwardly by a coiled spring l5 fitted in socket 9| of the upper valve disk 9 and held in place by boss I9l in top cap i6. Top cap IS is secured to the upper end of the main valve body I by threaded studs i? and nuts i8. The coiled spring positively closes the upper valve disk and' while the pres- `sure actuated suction stop valve is preferably arranged in a vertical position, it may, of course, be arranged in any other desired position as the coiled spring i5 will positively close the upper valve disk 9 and maintain the same firmly against its seat 8 when the pressure in the liquid line is reduced as hereinafter fully explained. The

top cap studs i7 are xed to the upper end of the main valve body and the nuts i8 engage amavo@ the upper face of the top cap which is pierced by the said studs I1. The top cap is provided at its lower face with a central boss i9 which extends into the upper end of the coiled spring and centers the same. The said top cap is also provided at its lower face with an annular rib 20 arranged concentric with the central boss i3 and adapted to bear against a. top cap gasket 2i which is iitted in an annular recess 22 in the upper end of the main valve body i. The annular rib 20 and the top cap gasket 2i form a gas tight joint between the top cap and the main valve body to prevent the escape of gas.

When the upper valve disk is closed, it shuts oi communication between the gas inlet and the gas outlet and prevents the flow of gas through the suction line. 'Ihe upper valve disk is connected by a piston stem 23 with a piston head 24 which carries a lower valve disk 25 and which operates in a lower cylindrical chamber 3. The piston stem 23 extends downwardly from the upper valve disk and is guided at 21 in the main valve disk body and its lower end is preferably threaded into the piston head 24 and provided with a jam nut 28, but the stem 23 which is shown tted in socket 92 of the upper valve disk 9 may be connected with the upper valve disk 9 and the lower piston head 24 in any other desired manner as will be readily understood.

'I'he piston head 24 is provided with piston rings 29 and the lower valve disk 25 cooperates With a valve seat 30 formed by a removable valve seat ring 3| preferably threaded into the main valve body I as indicated at 32. The lower edge of the valve seat ring 3| is bevelled to form the valve seat 30 and the lower portion 33 of the lower cylindrical chamber is enlarged forming anannular space below thevalve seat surrounding the lower valve disk 25 and the lower portion of the pistonv 24 The lower valve disk 25 is ofgreater diameter than the piston head 24 and is bevelled as shown to cooperate with the bevelled valve seat. 'Ihe piston 24 consists of a reduced cylindrical extension of the lower valve disk 25 and is preferably formed integral with .the same.

The lower end of themain valve body Iy is provided with an annular groove 34 for the reception of a check valve body gasket 35 and a check valve body 36 is secured to the lower end of the main valve body I by lower check valve studs 31 and'nuts 33. The check valve body conforms to the configuration of the main valve body and is provided at its upper end withan annular rib 39 which fits within the annular groove 34 of the lower end of the main valve body and bears against the lower check valve body gasket 35. The

studs 31 are fixed to the lower end of the main valve body and pierce portions of the upper end of the check valve body and the nuts 38 maintain the annular rib 39'in tight clamping engagement with the lower check valve body -gasket 35 to form a liquid and gasA tight connection to prevent the escape of any liquid or gas from the device.

opened to permit liquid to iiow through the liquid line to the evaporator H2.

The check valve body is provided with afliquid inlet'di` and a liquid outlet 32 and it has a liquid passage 43 connecting the liquid inlet and the liquid outiet and consisting of o horizontal branch or portion 4i and a vertical branch or portion 46. The horizontal branch or portion extends inwardly from the liquid inlet di and the. vertical branch 45 extends upwardly from the inner end of the horizontal branch or portion it to the liquid outlet 42. The liquid inlet and the liquid outlet are threaded for pipe connections and the gas inlet and the gas outlet are also threaded for the same purpose.

When liquid iiows through the liquid line it enters the liquid inlet of the lower check valve body and passes through the passage 43 which connects the liquid inlet with the liquid outlet and a portion of the liquid also enters the passage 90 through a chamber 46 communicating with passage 44 and having a lower reduced inlet portion 41 provided with a valve seat 48 with which a needle valve 49 cooperates for controlling the ilow of the liquid through the passage 90 and the admission of= the liquid pressure to the lower valve disk 25 and consequently the opening of the upper valve disk 9. By adjusting the needle valve 43, the opening of the valve disk 9 for permitting the Ailow of the gas through the main valve body may be retarded` to prevent damage to the valve by the high pressures employed.

The lower check valve body is also provided with a by-pass passage 50 connecting the main liquid passagev43 with the chamber 46 and the passage 44 so that the liquid may iiow freely from the lower cylindrical chamber 33 of the main valve body into the liquid line when the liquid stop valve is closed.

The needle valve 49 has a threaded portion 5I which engages an upper threaded portion 52 of a vertical opening or bore 63 in the lower end of the check valve body. This permits an adjustment of the needle valve 49 with relation to the tapered lower end of valve seat 460i the reduced portion 41 of the chamber 46s of the lower check valve body. The lower portion 54 of thebore or opening 53 is threaded to receive a gland 55 and packing 66 which is interposed between the gland 55 and a stuiling box washer 51 to form a stuffing box to provide a liquid and gas tight connection or joint around the needle valve for preventing the escape of liquid or gas. *The lower portion 58 of the check valve body is reduced and exteriorly threaded at 59 to receive a lower cap 60 interiorly threaded at the upper end to engage the threads 59 of the lower reduced portion 56 of the lower check valve body. A bottom cap gasket 6I is arranged between the upper edge of the bottom cap and the shoulder 62 formed by -a reduction of the lower portion of the lower check valve body.

Check valves are provided in the main passage 43 and in the by-pass passage 5u for purposes hereinafter described. The check valve of the main liquid passage 43 comprises a check valve disk 63 and a valve seat 64 consisting of an interiorly bevelled portion of a sleeve 65 arranged in a bore or opening 66 extending upwardly from the main passage at the inner end of the liquid outlet. The bore or opening 66 which extends from the main liquid passage to the upper end of the lower check valve body is of greater diameter than the vertical branch 45 of the main liquid passage 43 kand it forms a shoulder 61 surrounding the upper end of the vertical brancli 45 of the main liquid passage and receiving a gasket 68 which is engaged by the lower end of the sleeve 65. The lower end ofA the sleeve 65 is reduced interiorly and exteriorly to form an annular rib 69 for engaging the gasket 68. A retaining plug is threaded into the upper end of the bore or opening 66 and engages the upper end of the sleeve 65. The retaining plug 10 holds the sleeve tightly in engagement with the seat gasket 69. The sleeve is provided at the liquid outlet with opposite openings 'll and it has an exterior annular recess 12 which provides an annular space or passage around the sleeve for connecting the openings 1i to facilitate free passage of the liquid through the lower valve body.

The by-pass check valve comprises a check valve disk 13 arranged upon a check valve seat 14 of a sleeve 15 constructed similar to the check valve sleeve 65 heretofore described and arranged ina vertical bore or opening 16 extending from the chamber 46 and the by-pass 59 to the upper end of the lower check valve body. The bore or opening 16 is of greater diameter than the chamber 46 to form a shoulder 11 on which is seated a gasket 18. The lower end of the sleeve is reduced to form a-gasket engaging rib 19. Also the vsleeve is provided with opposite openings 80 and it has an exterior annular recess 8i forming a space around the sleeve at the said openings. The lower check valve body is provided with clean-out plugs 82 and 83 mounted in threaded openings 8d .and 85 which are arranged in line With the openings of the seat forming sleeves of the check valves.

The sleeve 15 is retained in the opening vor bore 16 by a retaining plug 86 threaded into the upper end of the borezor opening 16 and constructed similar to the threaded retaining plug 10. A ller block 4`orpiece 81 is interposed between the retaining plug 86 and the upper end of the sleeve. 1

The gas, passes through the main valve body in the direction of the arrow pointing toward gas inlet 4 in Figure 2 of the drawings and the liquid passes through the lower check valve body l in the direction of the arrow pointing toward liquid inlet 4| in Figure 2 of the drawings, the liquid flowing to the right in the said figure and the gas to the left. Starting from a closed position with the magnetic liquid stop valve of the refrigeration system closed, the thermostat of the refrigeration system opens the magnetic valve and permits the high pressure liquid to extend as far as the float valve g1 the expansion or cooling coil. As the liquid passes`through the lower check valve body which with the parts carried thereby constitutes the control assembly of the suction stop valve, pressure is applied to the high pressure piston which opens the valve on the suction line. When the desired temperature is reached in the refrigeration chamber, the thermostat closes the liquid magnetic stop valve and the oat valve releases the pressure between the magnetic stop valve and the evaporating coil. The lowering of the pressure on the piston on the i high pressure side of the suction stop valve allows the suction stop valve to close and further refrigeration is stopped until the magnetic liquid stop valve is again opened by the thermostat.

The pressure ofthe liquid entering passageway 43 will cause a portion of the fluid to pass needle valve 49, through liquid conduit 90 and into chamber 33 against the lower face of valve disk ,25; by'which'valve disk 25 will be raised against the action of spring I5 and thereby open suction valve 9 in passageway 1.

When Y refrigeration is discontinued and the liquid stop valve closed, the pressures in the liquid line and the suction line will be balanced until after closing of suction 'valve 9, which closing should be rather prompt for most efiicient operation of the refrigeration system. The closing of suction valve 9 is accelerated by means of check valve 13, which check valve will open under pressure of iluid returning from conduit 90, thereby permitting the uid to quickly pass through bypass 50 into fluid line 43.

Due to the great pressures involved, the opening aiorded by needle valve 49 is necessarily very small, normally a ring opening about 51g of an inch in width. When the magnetic liquid stop valve is closed by the thermostat, the pressure in chamber and in all of the channels of the control section of valve III) drops to the evaporator pressure. It will be readily appreciated that at the lower pressures the back ow of liquid through the small opening of needle valve 49 would be very slow. Since prompt response and consequent closing of the suction line is desired, check valve 13 is provided. The weight of piston 24 augmented by spring I5 causes the liquid in conduit 99 to raise the relatively light weight check valve disk 13 and permit the liquid from chamber 33 to pass out through conduit 50 and thence out pipe 42 to the evaporator Without delay. After the piston has dropped, check valve disk 13 reseats and remains seated until again urged upwardly when the magnetic liquid stop valve has opened and again closed.

Check valve 63 serves to prevent counter flow oi gas through the lower check valve body when the refrigerating system is not in operation.

The pressure in the liquid line to the evaporator or cooling or expansion coil will vary between the liquid cuto valve and the oat or thermal expansion valve. Between these two points the pressure will either be that of the condenser or liquid pressure or that of the evaporator or cooling coil, the pressure being dependent upon the opening and closing of the liquid stop valve which is determined by the desired temperature in the refrigerated space through the action of the thermostat. When refrigeration isrequired and the liquid stop valve is opened, the condenser pressure is applied to the piston of the suction valve which is greater than the combined pressure of the coiled spring and the evaporator or gas pressure on the upper valve disk 9' causing the valve disk 9 to open. The valve disk`9 remains in its open position as long as liq'uid is fed to the evaporator coil. When refrigeration is discontinued and the liquid stop valve closed,

e the pressure in the liquid line between the stop valve and the expansion or iloat valve is graduall'y reduced to the prssure inside of the evaporator and this permits the suction stop valve to close. The opening movement of the valve disk 9 is controlled by the needle valve of the control assembly so that the valve disk 9 will open at the proper time with relation to the flow of the liquid through the liquid line. As the device is entirely enclosed, it will operate under any moisaisance athwart the suction conduit, the stop section operable by pressure in the control section.

2. In a refrigerating system including a high pressure conduit and a low pressure conduit, pressure actuated means for rapidly closing the low pressure conduit, said means operated by pressure derived from the high pressure conduit.

3. In a refrigerating system including a high pressure conduit and a low pressure conduit having a stop valve and lan expansion valve in said high pressure conduit, means for closing the low pressure conduit comprising a pressure actuated valve provided with a control section interposed in the high pressure conduit between the stop valve and the expansion. valve.

4. In a refrigerating system including a high pressure conduit and a low pressure conduit having a stopvalve and an expansion valve in said high pressure conduit, an evaporator between the high pressure conduit and the low pressure c onduit, a compressor, means for closing the low pressure conduit comprising a pressure actuated valve provided with a control section interposed in the high pressure conduit between the stop valve and the expansion valve, said means for closing the low pressure conduit interposed in the low pressure conduit between the evaporator and the compressor.

5. In a refrigeration system including a low pressure gas conduit and a source of high pressure, means for rapidly closing said conduit operated by pressure derived from said source of high pressure. v l

6. In a refrigeration system including a fluid line having relatively highpressure and low pressure sections, a stop valve interposed athwart said high pressure section and said low pressure section whereby fluid flow through said low pressure section is controlled by fluid flow through 'said high pressure section, said stop valve provided with means operable by pressure fluid in said high pressure section to open said low pressure section when fluid is passing under pressure through said high pressure section, and means to accelerate closing said low pressure section when valve comprising a housing, a high pressure section passage in said high presssure section of the fluid line, a low pressure passage in said low pressure section of the fluid line, a valve normally seated closing said low pressure passage, a piston actuated means for unseating said valve in said low pressure passage, said piston actuated means providediwith a piston operable in a chamber communicating with said highpressure passage through a communication orifice, said high pressure section provided with a by-pass means between said communication orifice and said highpressure passage having a pressure actuated check valve interposed therein operable to accelerate closing of said low pressure valve upon release of fluid pressure in said high pressure section.

81 In a refrigeration s ystem including a iluid line having relatively high pressure and low pressure sections, a stop valve interposed athwart said high pressure section and said low pressure section whereby fluid ilow through said low pressure section is controlled by fluid ilow through said high pressure section, said stop valve pro vided with means operable by pressure of fluid insaid high pressure section to open said low pressure section when iluid is passing under pressure through said high pressure section, said stop valve comprising a housing, a high pressure section passage in said high pressure section of the fluid line, a low pressure passage in said low pressuresection of the fluid line, a valve normally seated closing said low pressure passage, a piston actuated means for unseating said valve in said low pressure passage, said piston actuated means provided with a piston operable in a chamber communicating with said high pressure passage through a communication orifice, means adjustable in said communication orice adapted to positively control flow volume from said high pressure passage through said communication orifice for timing the operation of said piston, said high pressuresection provided with a bypass means between said communication orifice and said high pressure passage having a pressure actuated check valve interposed therein operable to accelerate closing of saidlow pressure valve upon release of fluid pressure in said high pressure section.

9. In a'refrigeration system including a iluid line having relatively high pressure and low pressure sections, a stop valve interposed athwart said high pressure section and said low pressure section whereby fluid flow through said low pressure section is controlled by iluid flow through said high pressure section, said stop valve provided with means operable by pressure of fluid in said high pressure section to open said low pressure section when iluid is passing under pressure through said high pressure section, said stop valve comprising a housing, a high pressure section passage in said high pressure section of the iluid line, a low pressure passage in said low pressure section of the fluid line, a valve normally seated closing said low pressure passage, a piston actuated means for unseating said valve in said low pressure passage, said piston actuated means provided with a piston operable in a chamber communicating with said high pressure passage through a communication orice, means adjustable in said communication orifice adapted to positively control llow volume from said high pressure passage through said communication orifice for timing the operation of said piston, a by-pass between said high pressure passage and said communication orice having a pressure actuated check valve interposed therein operable to accelerate closing of said low pressure valve upon release of fluid pressure in said high pressure section, an'd a check valve in said high pressure passage to prevent counterilow of gas therethrough.

10. In a refrigeration system including a fluid line having relatively high pressure and low pressure sections, a stop valve interposed athwart said high pressure section and said low pressure section whereby fluid ilow through said low pressure section is controlled by fluid flow through said high pressure section, said stop valve provided with means operable by pressure of fluid in said high pressure section to open said low pressure section when uid is passing under pressure through said high pressure section, said stop vvalve comprising a housing, a high pressure secsaid high pressure passage through said communication oriice for timing the operation of said piston, a byfpass between said high pressure passage and said communication orice having a pressure actuated check valve interposed therein operable to accelerate closing of said low pressure valve upon release of fluid pressure in said high pressure section, and a check valve in said high pressure passage to prevent counterow of gas therethrough.

HARRY W. N EVIN. 

